Cannabis is an annual, primarily dioecious, flowering herb. The genera Cannabis is considered to be monospecific (Cannabis sativa L.) which is divided into several subspecies (C. sativa subsp.sativa, C. sativa subsp. indica, C. sativa subsp. ruderalis, C. sativa subsp. spontanea, C. sativa subsp. kafiristanca). However, the chemical and morphological distinctions by which cannabis has been split into these subspecies are often not readily discernible, appear to be environmentally modifiable, and vary in a continuous fashion. For most purposes, it will suffice to apply the name Cannabis sativa to all cannabis plants encountered.
Cannabinoids are chemical compounds found in the cannabis plant that interact with receptors in the brain and body to create various effects. Cannabis contains over 400 compounds including over 100 cannabinoids, which are aryl-substituted meroterpenes unique to the plant genus cannabis. The pharmacology of most of the cannabinoids is largely unknown but the most potent psychoactive agent, Δ9-tetrahydrocannabinol (Δ9-THC, or THC), has been isolated, synthesized and much studied due to its abundance and psychoactive attributes. Other plant-based cannabinoids include Δ9-tetrahydrocannabinolic acid, Δ8-THC, cannabigerol, cannabidiolic acid, and cannabidiol (CBD). These and other cannabinoids have additive, synergistic or antagonistic effects with THC and may modify its actions when cannabis products are consumed.
Cannabinoid containing extracts can be produced from a wide variety of methods (sub/supercritical CO2, hydrocarbons, alcohols, and by heated/pressurized means) and can be further purified using winterization (precipitation) in alcohols, distillation, or chromatographic separation. The resulting cannabinoids are highly lipophilic with Log P values ranging from 5 to 9, making them practically insoluble in water. These properties are not conducive to traditional pharmaceutical drug delivery methods, which is why smoking is still a preferred method for cannabis consumption.
It is well known in cosmeceutical and pharmaceutical preparations that above the critical micelle concentration of one or more surfactants that micelles will be formed during emulsification. The micelles can take many shapes (spherical, cylinders, or other arrangements), structures (unilamellar or multilamellar), and names (liposomes, niosomes, and ethosomes among others). Various reports have concluded that these micelles can also be used to encapsulate active ingredients for delivery of pharmaceuticals (Hung et al. 2001; Narang et al. 2007: Kwon, 2012) as well as increase the bioavailability of drugs with poor water solubility (Keller et al. 1999; Touitou et al. 2000; O'Driscoll et al. 2008).
Transdermal delivery allows for direct absorption into the bloodstream without a hepatic first pass effect that significantly reduces the bioavailability of cannabinoids. Despite efforts to create highly soluble and bioavailable cannabinoid formulations, there remains a need in the art for cannabinoid formulations that have increased bioavailability and which are conducive to use with traditional drug delivery methods.